Purpose: To compare the intraocular pressure (IOP) lowering effect and adverse effects of 0.5% timolol-2% dorzolamid (TD) and 0.5% timolol-0.2% brimonidine (TB) fixedcombination in patients with primary open-angle glaucoma (POAG) or ocular hypertension (OH).

Mateials and Methods: Forty-four eyes of 22 patients followed with the diagnosis of PAAG or OH and treated at least 6 months with only TD were enrolled to this study. The mean of the last three IOP measurements recorded when patients were using TD was calculated. After a month of washout period without topical therapy, the baseline IOP was measured. Then TB treatment was started 2 times daily. Follow-up visits were scheduled at 2nd and 4th weeks. IOP was measured and adverse effects were observed in these visits. Ocular discomfort with topical use of TB and TD was evaluated using a scale.

Results: Mean IOP measurement were 16.62±2.50 with TD, 15.46±2.52 with TB and 23.20±1.79 mmHg after washout period. TB fixed combination significantly reduced IOP (p<0.0001). A low statistically significant difference was observed between the mean IOP measurements obtained with TD and TB (p=0.04). Ocular discomfort scores were 2.00±0.55 with TD and 1.20±0.41 with TB (p<0.001). The side effects observed during the use of TB were conjunctival hyperemia in 3 patients, oral dryness in 5 patients and temporary blurred vision in1 patient.

Conclusion: In this study, we observed that the fixed combination of TB has significantly reduced IOP as good as TD, in patients with PAOG or OH. Also, TB was topically well tolerated with less ocular discomfort than TD.